Add Uphold Equities Card

[mandar-brave]

Add the Uphold Equities Card.
Here the card design

Link: https://uphold.com/en/buy-fractional-shares/brave

Lets make it a priority to get this shipped.
@NejcZdovc @jenn-rhim

[LaurenWags]

Verified passed with

Brave	1.17.62 Chromium: 86.0.4240.185 (Official Build) dev (x86_64)
Revision	37e6f852ed18086458552039ad26421aa9fc7acc-refs/branch-heads/4240@{#1377}
OS	macOS Version 10.14.6 (Build 18G6032)

Verified tests performed under brave/brave-core#6982 (comment)

US (no promo)	KY (has promo)

• ensured that the equities uphold card wasn't being displayed when using US (United States), DK (Denmark) & FR (France)
• ensured that the equities uphold card was being correctly displayed when using KY (Cayman Islands), NZ (New Zealand), & WS (Samoa) - all available on the list from https://github.com/brave/brave-core/pull/6982/files#diff-6b6ed7044cbb83bc4e57c74f9d946505e033ec70915527c7d525351b0a4c8e48
• ensured that the equities uphold card is visible when refreshing/re-opening brave://rewards
• ensured that the equities uphold card is visible after restarting Brave several times
• ensured that clicking on X closes the promo and ensured that it's never visible again (refreshing/re-loading/restarting)
• ensured that clicking on the card opens a new tab and loads the following:
  • https://uphold.com/en/buy-fractional-shares/brave --> https://uphold.com/en/buy-fractional-shares

---

Verification passed on

Brave	1.17.63 Chromium: 87.0.4280.49 (Official Build) dev (64-bit)
Revision	f77f85899646b42a1d3c8ff36794e00becab9171-refs/branch-heads/4280@{#1115}
OS	Ubuntu 18.04 LTS

• Verified that the promotion is shown for the following: NZ, ER, MH, PG

• all available on the list from https://github.com/brave/brave-core/pull/6982/files#diff-6b6ed7044cbb83bc4e57c74f9d946505e033ec70915527c7d525351b0a4c8e48
  

• ensured that the equities uphold card wasn't being displayed when using US (United States), PL (Poland) & DE (Germany)
• ensured that the equities uphold card is visible when refreshing/re-opening brave://rewards
• ensured that the equities uphold card is visible after restarting Brave several times
• ensured that clicking on X closes the promo and ensured that it's never visible again (refreshing/re-loading/restarting)
• ensured that clicking on the card opens a new tab and loads the following:
  • https://uphold.com/en/buy-fractional-shares/brave --> https://uphold.com/en/buy-fractional-shares

---

Verification passed on

• Verified that the promotion is shown for the following: NZ, ZW, CO

• all available on the list from https://github.com/brave/brave-core/pull/6982/files#diff-6b6ed7044cbb83bc4e57c74f9d946505e033ec70915527c7d525351b0a4c8e48
  

• ensured that the equities uphold card wasn't being displayed when using US (United States), PL (Poland) & FR (France)
• ensured that the equities uphold card is visible when refreshing/re-opening brave://rewards
• ensured that the equities uphold card is visible after restarting Brave several times
• ensured that clicking on X closes the promo and ensured that it's never visible again (refreshing/re-loading/restarting)
• ensured that clicking on the card opens a new tab and loads the following:
  • https://uphold.com/en/buy-fractional-shares/brave --> https://uphold.com/en/buy-fractional-shares